SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 1)
   ExpressionList (children 3)
    Function map (alias m) (children 1)
     ExpressionList (children 4)
      Function CAST (children 1)
       ExpressionList (children 2)
        Literal \'1\'
        Literal \'LowCardinality(UInt8)\'
      Literal UInt64_4
      Function CAST (children 1)
       ExpressionList (children 2)
        Literal \'2\'
        Literal \'LowCardinality(UInt8)\'
      Literal UInt64_5
    Function mapKeys (children 1)
     ExpressionList (children 1)
      Identifier m
    Function mapValues (children 1)
     ExpressionList (children 1)
      Identifier m